Expression of the cyclooxygenase-2 gene in gastric epithelium.
This study examined the mRNA level of cyclooxygenase-2 (cox-2) in a rat gastric mucosal cell line after growth stimulation in vitro and in rat gastric mucosa before and after acid-induced injury in vivo. RGMI cells were stimulated with fetal calf serum in the in vitro study. Thereafter, the cox-2 mRNA level was examined by Northern analysis. Effects of NS-398, a specific inhibitor of cox-2, and indomethacin on prostaglandin production and cell proliferation were examined in RGM1 cells. In the in vivo study, rats were given 1 ml of 0.6 N hydrochloric acid into the stomach. The level of cox-2 mRNA was examined in rat gastric mucosa after acid administration. Cox-2 mRNA increased 20-60 min after growth stimulation in RGM1 cells. Both NS-398 and indomethacin suppressed prostaglandin production and cell proliferation after growth stimulation. Expression of cox-2 mRNA was observed 40 and 60 min after administration of 0.6 N HCl. Gastric lesions developed within 60 min after HCl administration and healed significantly within 48 h. The present study shows the expression of cox-2 in gastric epithelial cells in vitro and in gastric mucosa after injury in vivo. The results also suggest that cox-2 is involved in de novo synthesis of prostaglandins and cell proliferation in gastric epithelium.
Sawaoka
H
H
First Department of Medicine, Osaka University School of Medicine, Suita, Japan.
Tsuji
S
S
Tsujii
M
M
Gunawan
E S
ES
Nakama
A
A
Takei
Y
Y
Nagano
K
K
Matsui
H
H
Kawano
S
S
Hori
M
M
D000818:Animals; D002460:Cell Line; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D015870:Gene Expression; D006851:Hydrochloric Acid; D007213:Indomethacin / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D009578:Nitrobenzenes / Q000494:pharmacology; D010544:Peroxidases / Q000096:biosynthesis* / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013449:Sulfonamides / Q000494:pharmacology; D013997:Time Factors
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D009578:Nitrobenzenes; D012333:RNA, Messenger; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D010544:Peroxidases; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D006851:Hydrochloric Acid; D007213:Indomethacin